At least 40 people, including several children, have been killed in a series of attacks by insurgents across the Iraqi capital Baghdad.

Two car bombs exploded on Saturday, one packed with explosives near a market in Sadr City, killing 12 people and wounding 27.

Half an hour later, 10 people died and 31 were injured after a bomb went off in a bus station.

Hours earlier, a roadside bomb planted near an open-air market in the eastern neighbourhood of Maamal killed eight people, including four children at a playground.

Police said another 24 people, including youngsters, were wounded in the blast.

Elsewhere, a bomb planted on a bus carrying Iranian pilgrims to a Baghdad shrine, killed five people and injured nine.

It exploded around 300 metres from a police checkpoint, sending the bus out of control before it flipped over on its side.

Image Caption:The scene of the blast in Maamal, in eastern Baghdad

In the northern city of Mosul, gunmen broke into the houses of two families, killing a boy and his parents in one and a mother and daughter in the other, according to police.

A bomb exploded near the house of another household, wounding six family members.

In Tuz Khormato, about 130 miles north of Baghdad, a car bomb exploded injuring 11 people, including three children.

UN special envoy Martin Kobler condemned Saturday's violence as "atrocious," adding in a statement: "The targeting of worshippers is an appalling crime."

No-one has yet claimed responsibility for the attacks.

They are the latest in a spate of violence in the past week that has broken a relative calm, even though authorities had announced moves to boost security during Eid al Adha, a four-day Islamic religious festival.